As embedded system designs continue to increase in complexity and
development schedules grow tighter, reducing development time is a key
consideration in MCU selection for motor control applications. The
C8051F85x/6x MCU-based motor control reference design makes the
developer’s job easier by providing cost-effective hardware and
production-quality firmware for quick evaluation and deployment in
cost-sensitive BLDC applications. In addition, the motor control
graphical user interface (GUI) gives developers greater flexibility and
ease-of-use when controlling and understanding BLDC motor operation, and
access to production-ready motor control source code helps to expedite
the design-in time.

The sensorless BLDC motor control reference design uses a C8051F850 MCU
to control a BLDC outrunner motor (typically found in toy helicopters)
mounted on the motor mount board. The powertrain board contains gate
drivers, power MOSFETs, a current sensing resistor as well as resistor
dividers to attenuate motor phase voltages so that they can be measured
by the C8051F85x/6x MCU. The MCU board contains a C8051F85x/6x MCU, as
well as buttons to start/stop and change motor direction and reset the
MCU. The MCU’s PWM output drives the gate drivers on the powertrain
board. The MCU board also contains an operational amplifier (op-amp) to
amplify the current sensing voltage so it can be measured by the MCU.

The C8051F85x/6x family is ideally suited for BLDC applications because
of its best-in-class analog performance, small footprint and other
features optimized for motor control designs. The cost-effective,
high-performance 8051-based MCU spins the reference design kit’s 6-pole
motor at a maximum speed of 50,000 rpm. The C8051F85x/6x MCU family also
helps developers reduce overall system cost by eliminating the need for
external components such as a crystal oscillator, voltage reference,
level shifters, temperature sensor and other discretes.

Silicon Labs’ sensorless BLDC reference design is designed to give
developers a productive, comprehensive “out-of-box” experience,
providing everything needed to get a motor spinning in less than five
minutes. The reference design includes the following hardware and
software tools:

C8051F850 MCU control board providing the intelligence to drive the
motor and associated peripherals

“Rapid application development, reduced system cost and fast time to
market mean everything to embedded developers working on cost-sensitive
motor control designs,” said Diwakar Vishakhadatta, vice president and
general manager of 8-bit MCU products at Silicon Labs. “We created our
sensorless BLDC motor control reference design to help make the
developer’s job easier and more productive and to highlight the
significant benefits in designing BLDC systems based on our popular
C8051F85x/6x MCUs.”

Pricing and Availability

Silicon Labs’ C8051F850-BLDC-RD motor control reference design is
available today and priced at $164.99 (USD MSRP). Samples and production
quantities of Silicon Labs’ C8051F85x/6x MCUs are also available now.
MCU pricing in 10,000-unit quantities begins at $0.40 (USD), and high
volume pricing starts at $0.30.

For additional information about the sensorless BLDC motor control
reference design and to order MCU samples and download complimentary
Keil development tools, please visit
www.silabs.com/smallmcu.

Silicon Labs

Silicon Labs is an industry leader in the innovation of
high-performance, analog-intensive, mixed-signal ICs. Developed by a
world-class engineering team with unsurpassed expertise in mixed-signal
design, Silicon Labs’ diverse portfolio of patented semiconductor
solutions offers customers significant advantages in performance, size
and power consumption. For more information about Silicon Labs, please
visit
www.silabs.com.